Compress Video Files Without Uploading to Any Server
BigWow's Video Compressor runs FFmpeg compiled to WebAssembly directly in your browser tab. The entire transcoding pipeline executes on your local CPU without any file being uploaded to a cloud server.
FFmpeg runs as a WebAssembly binary — no server-side processing.
0 bytes of video data are uploaded to any external server.
Supports MP4, WebM, MOV, and AVI input formats locally.
Frequently Asked Questions
Is it really possible to compress video entirely in a browser?
Yes. Modern browsers can run WebAssembly at near-native speed. BigWow loads a Wasm build of FFmpeg that executes the compression entirely in your browser's memory.
Will compressing video in a browser be slower than a desktop app?
It can be, depending on your hardware. WebAssembly runs at roughly 80–90% of native speed. For most files under 500MB, compression completes in seconds to minutes.
Sources & References
- WebAssembly (Wasm) W3C specification enabling native-speed code execution in the browser.
- FFmpeg documentation for H.264 CRF-based video compression.
Try it now — 100% free, zero upload
No account, no ads, no file size limits. Opens instantly in your browser.